Abstract

The dynamics of the break-up of curved jets produced by the prilling process vere studied. The effects of liquid dynamic viscosity, rotation rate and orifice size upon the surface tension driven instabilities were investigated. Liquid dynamic viscosity was varied by using mixtures of glycerol and water which gave dynamic viscosities ranging from 0.001 to 0.081 Pa.s at 20°C. Over the range of experimental parameters studied, four different break-up modes were identified. For each mode, considerable differences in the break-up mechanism and in the drop size distributions produced were observed. Dimensional analysis has shown that the break-up modes can be predicted from a plot of Reynolds number against Weber number. The break-up mode observed is a strong function of viscosity and highly non-linear effects were observed with the most viscous solutions used. The effect of rotation rate on the jet break-up length was inconclusive from the experiment.